


Mirrors And Opposites

by lightofdaye



Category: Harry Potter - J. K. Rowling
Genre: Bets & Wagers, Blow Jobs, Cunnilingus, Exhibitionism, Explicit Sexual Content, F/M, Seduction, Slytherins Being Slytherins, Voyeurism, Wall Sex
Language: English
Status: Completed
Published: 2017-01-09
Updated: 2017-01-09
Packaged: 2018-09-16 12:14:24
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,664
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9270734
Author URL: https://archiveofourown.org/users/lightofdaye/pseuds/lightofdaye
Summary: Astoria and Daphne make an ill-considered bet.





	

**Author's Note:**

  * For [LRThunder](https://archiveofourown.org/users/LRThunder/gifts).



_“A sister is both your mirror – and your opposite.”_ – **Elizabeth Fishel**

\---

“That right there,” Astoria Greengrass said to Daphne one evening at dinner, “is my future husband.”

Daphne Greengrass rolled her eyes and then followed the direction of her sister’s nod. It did not clarify things much. The far end of the Slytherin table was extremely crowded. In fact, this end of the Slytherin table was extremely crowded, as was _every_ House table, owing to the fact that there was an extra year’s worth of students packed in amongst the regular seven years of students.

Of course that was what happened when instead of having proper NEWT examinations the school became a pitched battleground. Daphne had not taken part in either side of the Battle of Hogwarts, partly because of her own unwillingness and partly because the defenders had not trusted anyone from Slytherin house to stay. 

Their entire previous year’s education had retroactively been considered unacceptable to the ministry though, so even if they had had exams, Daphne thought any results would have been considered null and void. She wasn’t looking forward to taking all her NEWT exams in eight month’s time with Astoria, now a seventh year herself, right next to her.

On the other hand, she certainly didn’t miss the ‘Dark Arts’ class that had replaced Defence in the previous year but she had considered it prudent to continue taking Muggle Studies. She had expected it to be the same propaganda as before; just in the opposite direction but to her surprise she was beginning to enjoy it. The various ways Muggles did things to cope with not having magic were quite ingenious some times. Even if she still couldn’t understand how aeroplanes were supposed to work.

“Well?” Astoria said impatiently.

“Well what?” Daphne forced her focus back to the conversation. “I wouldn’t marry Zabini if I were you, he might have his mum’s approach to the whole thing.” 

“Zabini?!” Astoria hissed. “I don’t want to marry Zabini. To his left.”

Daphne’s eyes skimmed the seats to Blaise’s left. Her heart sank a little but responded gamely. 

“Oh, Goyle is it? Well, the heart wants what the heart wants, Sis.”

Daphne could almost feel the force of her glower.

“You’re doing that on purpose,” she stated flatly. “I’m talking about Malfoy.”

“You are,” Daphne said. “For Merlin’s sake why?”

“Have you looked at him recently? He’s so dreamy and handsome!” Astoria chirped. “And brave too, he had the Dark Lord in his house all the time and he still stood up to him. You know he saved Potter.”

Daphne pinched the bridge of her nose. She had had classes with Draco Malfoy for the vast majority of the last 7 years of school and she very much doubted Malfoy had saved anything but his own skin.

“Why are you telling me this?” Daphne asked. “It can’t just be to see the funny disgusted look on my face.”

“You know him, you could introduce us!” Astoria said.

“Yes, but I’m not going to,” Daphne said flatly.

Astoria had never been good at being refused. She pouted and when that didn’t work (and it never did with Daphne, she was happy to say) she counter-attacked.

“You’re just jealous.”

“Jealous? Of what?”

“Seven years and I bet he’s never looked twice at you. No-one has. They barely know you exist.”

“And they don’t know you exist at all,” Daphne shot back, annoyed despite herself. Astoria always knew her sore spots.

“Well I’m going to change that and do a damn sight better job than you would!” 

“I rather doubt that. I’d bet I could wrap anyone here around this.” She pointed her little finger at Astoria. “If I wanted to.”

“Done!” Astoria said. “I'll pick someone for you to seduce. And when you lose that bet, you have to introduce me to Draco.”

“Fine and when I win, you’re not allowed to make a move on Draco without Pansy’s express permission.”

“Done,” Astoria repeated, though colour rose in her cheeks. “Now to pick your target.”

Her eyes swept the hall back up to the other end of the table to the boys they’d considered before.

“Gregory Goyle.”

“Yes!” said Daphne extended her hand quickly. Too quickly, Astoria backed off quickly.

“No, no, embarrassing but too easy. Hmmm. Let me think...”

At that moment a small cheer went up from three of the houses and as they glanced at the entrance. A handsome if short, black-haired, green-eyed young man, flanked by a towering redhead who was holding hands with a bushy haired witch, was looking embarrassed. Harry Potter was receiving his usual hero’s welcome to breakfast and, as usual, was blushing and trying to dodge the attention.

Daphne’s gaze lingered a moment on him before returning to Astoria and noticing her widening evil grin.

“Oh no. No, no, no,” Daphne said, forcing a look of apprehension on to her face.

“Oh yes,” Astoria said firmly. “Your target is Harry James Potter.”

Daphne stared at her for a moment, struggling to conceal her emotions. But Astoria was resolute and Daphne shook her hand to seal the deal. 

\---

It didn’t take Daphne long to finish eating after they’d shaken hands. Astoria was just contemplating her dessert when Daphne placed her spoon and her bowl and made to rise. Astoria blinked.

“Where are you going?”

“No time like the present,” Daphne said briskly.

“You’re going now? In the middle of the Great Hall?”

“Yes,” Daphne said and turned and headed the opposite direction from the door to the entrance hall, to the farthest house table. 

_That was crazy_ was Astoria’s first reaction, opening her mouth to object again, but then she settled down, realising that she would win the bet very shortly.

Still she was surprised at the tack Daphne was taking. Just marching up to someone and trying to seduce them right off was a bad idea. Especially Harry Potter. He’d never stuck Astoria, in what little attention she paid to such things, as an outgoing person. He had his two friends and that seemed to be enough. Doubly so when approached by a Slytherin.

Daphne could surely see the looks she was getting from the Gryffindors as she sidled up between the table and the side of the Great Hall and their wariness only intensified as she got closer and closer to Harry. The look that a small redheaded witch was giving her was particularly murderous and no-one else looked particularly pleased to see a Slytherin in their midst.

She was doing something Astoria had not seen her do. She was starting a conversation. Daphne didn’t do that. She must really want to protect perfect Pansy’s claim to Draco to do this; Astoria was quite sure Parkinson would not fully appreciate the gesture.

Potter reddened slightly and those around him had stiffened on their benches, and Astoria was sure Daphne was going to be given the heave-ho. But then Potter opened his mouth and responded to her, though, Astoria could not hear the words. She edged closer.

Well, his fans said he was polite and well-spoken after all, it’s not like he’d just send her packing without a word….

Still, it wouldn’t long. Not with the mess Daphne was making of it. She had no subtlety at all, Astoria thought. Starring at him and playing with her hair like that and she bet Daphne was even batting her eyelids at him. Potter would see through that it about a second!

Daphne’s high pitched laughter reached Astoria’s ears, followed by a melodious chuckle that had to be Harry’s.

Astoria fumed. He couldn’t be falling for this, he just couldn’t with all that talk about his great character and moral fortitude he wouldn’t just.

Aha! Daphne had apparently overdone it at last. She’d reached out and ran her fingertips over the back of Harry’s hand. He jerked slightly as if shocked and the following questions and responses, though Astoria had only edged close enough to barely hear them, sounded shorter and more curt.

She felt a surprising amount of relief when her sister got to her feet and headed back to the entrance of the Great Hall. That introduction was in the bag. But then her heart crashed again as, before Daphne had even reached the door, Potter rose from the table to follow her.

Astoria froze, thinking hard. It had to be a coincidence! There was no way Daphne could have made that much progress that quickly. It would have taken Astoria herself two or three conversations to gain his trust. No, she didn’t have to worry; they weren’t going to meet up. 

A horrifying thought struck Astoria. _That Conniving So-and-So!_ She thought, Daphne didn’t actually have to succeed, she just had to put on a good show in front of her, sneak off and then claim to have done the deed. No muss, no fuss, easy victory.

Abandoning her meringue, Astoria leapt to her feet and followed them out of the hall in a rush. She almost missed Potter but just caught which passage out the Entrance Hall he took. All she had to do was follow him back to his common room and see he didn’t meet anyone and then she could throw Daphne’s false claims back in her face!

She hurried to follow him, once again only rounding a corner in a corridor just in time to see which one Potter was taking. She frowned. He wasn’t taking a route to the towers at all but she had to rush to keep up. Astoria didn’t like rushing; it was far too much like hard work for her liking. Astoria’s heels clattered on the tiles of the corridor in her haste and she was half sure that Potter had slipped through her grasp. She fumed. _This can’t be happening!_

She half-rounded the corner and then leapt back, so only a sliver of her face was showing past the wall. The single, round blue eye that could see into the next passage widened dramatically at the sight.

The corridor was not empty and her sister was not alone in it. 

Daphne was pushed up against the wall by a young man with black hair, Astoria couldn’t see his face but it was hardly a mystery who he was.

Harry Potter was nuzzling at Daphne’s neck, placing kisses against her throat. Her eyes were half closed, her expression delighted. The top several buttons of her blouse were undone and the garment had fallen open, revealing pink lace, bright against the white fabric of the uniform and her pale skin.

Worst of all, Daphne’s skirt was hiked up and Potter’s hand was disappearing under it. Astoria absolutely did not want to know where that hand was, but she did. The hand was _moving_ and Astoria could see Daphne’s mouth part slightly and, though it must surely have been her imagination, she thought she could hear the pleased moan escape those lips.

Astoria’s mouth was dry, there was a strange sensation in the pit of a stomach, an achy, fluttering sensation, like she was excited at what she was seeing.

Daphne caught sight of her and there was the slightest raise of an eyebrow, the wink of an eye and then she returned her attention to Potter, tugging him closer.

Spurred into sudden action, Astoria retreated quickly.

\---

The clattering of heels was fading when Harry’s mouth moved up from her neck to whisper in her ear.

“I think your friend got a good view,” he said softly.

“Hmm?” Daphne was hardly in a position to respond more intelligibly than that as Harry’s magic fingers ceased thrusting inside her and instead started to trace maddeningly slow circles around her clit.

“Whoever you had following us had quite a show,” he said, curiously. “Was that your plan all along?”

“A-am I only allowed one motive?” Daphne said, shakily. “That would be quite boring.”

“I think I could make it worth your while if you wanted me to.” The confidence in Harry’s voice should have been annoying but instead Daphne’s pulse quickened, she bit back a squeak as Harry’s fingertips dipped into her pussy again. 

“Maybe you would. Maybe.” Daphne attempted a confident drawl but Harry did not look convinced. “You want to find an abandoned classroom and try to convince me?”

“I thought you’d never ask,” harry said and not without a certain amount of reluctance, he removed his hand from her knickers and offered a hand, the other one, to her. Hand in hand they walked, competing in nonchalantness, to the nearest unlocked door on the corridor and slipped through into the abandoned classroom beyond.

Harry wasn’t tall but even he was a few inches taller than Daphne and that few inches made all the difference when he was standing close to her, looming and strong. He lowered his face to hers and his mouth covered her lips firmly. They kissed deeply, Harry’s tongue darting into her mouth in quick, snake like movements. 

Their hands started to wander. Daphne’s blouse, already loose, was the first to go and her fingers slipped inside Harry’s shirt, tugging and tearing until buttons slipped free or broke off entirely. She tugged at it and it fell free displaying a stripe of bare pale skin and dark curls of hair on his chest.

Quick fingers traced around her body and made quick work of her bra, casting it aside atop her blouse. Harry gazed at her topless form and Daphne blushed, feeling the heat of his gaze. His hands lifted and almost hesitantly grasped her breasts. Daphne sighed and arched her back, pushing herself more into his grasp. His touch was soft and gentle and he fondled her with something approaching reverence.

With her eyes half-lidded, she reached out, groping blindly with her hands. Her grip fell to rest on his waist and instinctively she tugged him closer. His hands left her breasts to wrap around her body and she was pressed tight to his chest. 

His hands wound through her hair and she felt the elegant golden knot she’d spent a quarter of an hour perfecting that morning come loose as her hair tumbled freely past her shoulders, tickling at their bare skin as they snogged.

She should have been cold standing in a classroom half naked, but she was far from it. She was sandwiched between the classroom wall and Harry’s body, both of their bodies warm with exertion and desire and she could feel the increasing pressure a hardness pressed between her legs.

At least until Harry stopped kissing her mouth and moved downwards, cold air washing over Daphne’s bare chest.

“Harry what are yo- oooh!” Daphne’s question broke off as Harry sank to his knees, his nimble touch divesting her of skirt and knickers, her last remaining clothes other than shoes and socks.

And then his mouth went to work, eloquently. Daphne’s fingers twined through fine black as he started to lap at her cunt. She had only a few moments to be surprised; a Slytherin would never have done this, not without negotiations and repeated assurances that their would be reciprocation but Harry didn’t seem worried about that. Or perhaps he simply enjoyed doing the act enough that he didn’t care about receiving it in return.

Daphne quickly stopped caring as his practised tongue got up to speed. He licked at her cunt, toying it over her folds with a soft tongue before hardening it and plunging it into her.

His hands gripped at her hips, holding her in place and she clutched at his head, letting out a low keening cry as he sucked her clit. She could feel her wetness seeping out of her and probably soaking his face . She cried again breathlessly and her legs trembled as Harry let out a long, low groan of contentment that sent vibrations shooting through her.

She was just starting to worry about managing to stay upright, when Harry changed the rules on her again, leaving off with her just on the cusp of release and bounding to his feet, his hands pushing down his own trousers and underwear.

Daphne found herself swept off her feet, supported half by the wall and half by Harry’s hand’s firm grasp on her arse. Her legs were spread wide around his waist and were a few inches off of the ground. She gazed at him in surprise. The expression on his face was a mixture of ardency and embarrassment.

“Err...” he said, his face pink. “Give me a hand, please?” 

It took her moment for Daphne to realise what he meant, but of course he had his hands full. She reached down between their legs and grasped his cock. She couldn’t see it but it felt warm and thick and pulsed in her hand. After a moment, and with intense concentration to defeat the distraction of rubbing his cockhead against her folds, she got them lined up.

“Oh,” she whimpered as Harry pushed forward, slowly but relentlessly.

“Oh, fuck!” Harry said as she squeezed herself tight around the length of his cock.

Then he start rocking his hips back and forth, thrusting his cock in and out of her. His legs spread slightly wider to support their weight. She gripped at his back and wrapped all her limps about him as tightly as possible. 

Harry fucked her hard and fast, perhaps to make up for his early gentleness. Each motion a powerful rising thrust from his leg, each one drawing a loud moan from Daphne’s lips, a quiver from her body and a rounding slap of his skin against her wet cunt.

Daphne was past caring about her plans, about her sister, or about anything much other than the feelings of the here and now. Her tangled hair felt like a veil over, half-closed, unfocused eyes. Her limbs shook and the sensations shot through her body. She clenched down on him, helpless in the throes of a quite spectacular orgasm.

Harry groaned something incomprehensible and let a bit of her weight down, her feet dropped down to floor to support her but neither of their legs seemed to be fully functional. 

Harry staggered and sat down in an a seat, and Daphne dropped into a kneeling position, gazing at him. He was still hard. His cock jutting out proudly, glistening. Daphne didn’t think about what that wetness was, she just crawled towards him and wrapped her mouth about it, drawing the sweetest moan out of Harry’s lips. Daphne liked the sound of it. Her head bobbed, her tongue worked on the head, her hands pressed against the inside of her leg, she smelled sweat and musk, and he filled her mouth but she concentrated on making him cry out inarticulately as much as he had made her sing. 

His hands reached out and caressed her face and she realised he was clearing her messy of blonde hair away from her face. She looked up and their gazes met. She heard her name burst from his lips and then her mouth was flooded with thick salty come and she was coughing.

Afterwards, they were both panting, Harry limp in the chair and Daphne rose shakily and perched on his leg. His arms went around her waist, hers about his neck.

“That… amazing,” Harry managed to say.

Daphne made a soft noise of contentment into the crook of their neck. Neither of them were going to be up to much witty repartee for a while yet, not to mention moving anywhere.

\---

Daphne looked different when she returned into the common room, Astoria noted darkly. The clothing settled just slightly differently if you were looking you could tell it had been taken off and put back on again. Her hair was smooth and silky and pulled back in a similar but simpler style than Daphne had left the common room with that morning.

She walked up to Astoria in something just short of a saunter and sat down in the chair next to her. 

They sat in silence for a while. Daphne casually inspecting her nails while she waited. Astoria glowered and refused to say anything; she could be more stubborn than her sister if she wanted to.

“I’m waiting,” Daphne said after a while, apparently now completely certain, incorrectly, her nails were flawless. 

“For what?” Astoria said darkly.

“For you to gracefully concede that I have won our little wager,” Daphne continued, ignoring her tone. “And in record time, I might add.”

“By cheating!” Astoria hissed.

“Really?” Daphne said, calmly. “How?”

“You charmed him!”

“Wasn’t that the idea?”

“With magic?”

“Oh no. Just personality. Did you see me use a wand?”

“Or a love potion!” Astoria was not ready to give in.

“You do know how long those take to make right? Where would I find the time? Or slip it to him in front of all his other friends?” 

“Other friends?”

“Other than me. We’re quite close you know.” She really was insufferable, Astoria thought.

“Then how?”

“A good witch never reveals the secret of a trick,” Daphne said with an attempt at primness, but then she learned and a corner up of her lips quirked upwards as she continued in a more conspiratorial tone. “Unless you do want to admit you lost the bet?”

Astoria slumped. Defeated.

“All right, all right. You win!”

“Great!” Daphne leaned back in her chair, smiling smugly. “And just to to ease your mind. It’s a lot easier to seduce someone when you’ve already dated them for the last two months.”

Astoria gaped for long seconds. And then as anger burned up inside her, her mouth clicked shut.

“So you did cheat,” she said, each word clipped and hard.

“I didn’t pick the target,” Daphne said.

“You tricked me,” Astoria insisted.

“Whatever else you think of me, dear sister, remember this,” Daphne said slowly and clearly. “You don’t make bets that you haven’t already won. That’s the Slytherin way.”


End file.
